Coolant circulation problem

Coolant circulation problem

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Spanish S2

Original Poster:

341 posts

139 months

Friday 10th July 2020
quotequote all
Strange one this, the last couple of times I've checked the coolant level the expansion tank has been full
and the swirl pot level low, this has never happened before in 7+year's of ownership. The pressure cap
has always been on the expansion tank with no problem's in the Spanish heat. There's no air in the
system and the fan comes on and off normally. When it's cooling down it's obviously not sucking coolant
back to the swirl pot, anybody got any idea's.

WotnoV8

220 posts

92 months

Friday 10th July 2020
quotequote all
Have you checked the hose from swirl pot to expansion tank? Might be partially collapsing inside? Just a thought.
Sure someone will be along and have a much clearer idea of what may be the problem.

v8s4me

7,264 posts

226 months

Friday 10th July 2020
quotequote all
Why not try putting the pressure cap on the swirl tank and see what happens? Make sure it is one of the ones that allows coolant to bleed back into the swirl tank from the expansion tank as it cools. Check the rubber seal and spring on the pressure cap while you're at it.

Just a thought - you haven't got two pressure caps have you?

mk1fan

10,652 posts

232 months

Friday 10th July 2020
quotequote all
I say check the hose between the two first - and the pipes they connect to - the plastic expansion tank has a steel pipe that will rust (or I maybe mixing up with the Wedge one) If all clear then might just simply be an air lock.

When was the last time the coolant was flushed and renewed? Could be excess cavitation in a degraded fluid.

Or could be the caps are wrong / broke / being Bolschy.

How's Spain? Would love to do another tour and meet up again.

GreenV8S

30,484 posts

291 months

Friday 10th July 2020
quotequote all
If the blanking cap is leaking, it may not hold enough vacuum to draw coolant back from the expansion tank.

This also means the system may not be holding pressure and may be losing coolant due to evaporation, so is not something to ignore.

Spanish S2

Original Poster:

341 posts

139 months

Saturday 11th July 2020
quotequote all
Hi all, thank's for the feedback,I've replaced both cap's ( blanking and pressure ) I had new one's in stock,
I've also replaced the hose from swirl-pot to expansion- tank as a precaution, as well as changing the
coolant. Early indication is it's working normally.
Hi Stu, Spain is hot where I am at the moment, I did enjoy the rumble of the TVR's arriving at Lorca castle
hotel that night, that must be about 5 year's ago, how time fly's.

GreenV8S

30,484 posts

291 months

Saturday 11th July 2020
quotequote all
Check the condition of the faces that the caps seal against, too.